Printer

ABSTRACT

A printer using a roll of paper having an easy structure and ease of maintenance.  
     A bottom plate ( 10   a ) of a printer body unit ( 10 ) is attached to a bottom plate ( 31 ) of a connecting member ( 30 ). At the side wall ( 32 ) of the connecting member, a cutter unit ( 20 ) is attached so as to be rotatable around the pivot P. A platen ( 40 ) is attached to the cutter unit through a platen support member ( 50 ). A print head ( 12 ) has a printing surface ( 12   a ) and a rear surface ( 12   b ). The printing surface and the rear surface are arranged substantially perpendicular to the bottom plate ( 10   a ) of the printer body unit. When the printer is not used, the cutter unit is rotated upwardly at about 90 degrees, so that the platen is located on the non-printing surface side of the print head, opposite to a printing surface, with respect to a rear surface of the print head. Thus, the place above the print head becomes widely open, and the maintenance of the print head can be easily operated.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a printer using a roll of paper.

[0003] 2. Description of the Related Art

[0004] In a printer using a roll of paper, because a print head,especially a thermal head, is pressed against the paper during printingand is heated, it gets dirty easily and requires periodical maintenance.Thus, it is required to achieve easy access to the print head at thetime of maintenance, and various types of printers has been developed.

[0005] For example, FIG. 6 shows a printer wherein a platen 40 isattached to a roll cover frame 2 which is rotatably attached to a rollholding frame 1 for holding a roll of paper R. Because the platen 40 canbe widely separated from the print head 12, the maintenance of the printhead becomes easy. However, a stationary blade 21, which cooperates witha movable blade 22, driven by a cutter unit 20, to cut the paper, isalso attached to the roll cover frame 2. Thus, there is a problem thatthe adjustment of the relative positions of the movable blade 22 and thestationary blade 21 to realize favorable cut of the paper is difficult.

[0006] Also, as shown in FIG. 7, there is a printer wherein thestationary blade 21 is attached to the cutter unit 20 and the cutterunit 20 can be rotated. In this type of printer, because the stationaryblade 21 and the movable blade 22 are attached to the same cutter unit20, the above mentioned problem that the adjustment of the relativepositions of the movable blade 22 and the stationary blade 21 isdifficult does not occur. However, in order to separate the platen 40from the print head 12, at first the cutter unit 20 is rotated toseparate the stationary blade 21 from the print head 12, and then, theroll cover frame 2 is rotated to separate the platen 40, that is, twomotions are required.

SUMMARY OF THE INVENTION

[0007] An object of the present invention resides in providing a printerusing a roll of paper having a simple structure wherein a print head canbe accessed by a simple operation.

[0008] According to the present invention, there is provided a printerusing a roll of paper, comprising a printer body unit having at least aprint head attached thereto and a cutter unit for cutting the paperprinted by the print head, wherein the cutter unit is rotatably attachedto the printer body unit, the cutter unit includes a stationary bladeand a movable blade which cooperate, above the print head, to cut thepaper during the cutting operation, the print head is provided with aplaten for pressing the paper against the print head, and the stationaryblade, the movable blade and the platen can be displaced from a positionabove the print head, by rotating the cutter unit.

[0009] Preferably, the cutter unit can be rotated to a position in whichthe platen is located on the non-printing surface side of the printhead, opposite to a printing surface, with respect to an extension lineof a rear surface of the print head, when the printer is not used.

[0010] Preferably, a connecting member is attached to the printer bodyunit and the cutter unit is rotatably attached to the connecting member.

[0011] Preferably, the platen is attached to a lower surface of thecutter unit through a platen mounting member.

[0012] Preferably, the platen mounting member can also serve as a paperguide for guiding the paper into the cutter unit.

[0013] The present invention may be more fully understood from thedescription of preferred embodiments of the invention set forth below,together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows a printer which is in an inoperative position, formaintenance of a print head, in a first embodiment of the presentinvention.

[0015]FIG. 2 shows a printer in use in a first embodiment of the presentinvention.

[0016]FIG. 3 shows a partial, detailed view of FIG. 2.

[0017]FIG. 4 shows an exploded view of a first embodiment.

[0018]FIG. 5 is an explanatory view of a second embodiment.

[0019]FIG. 6 shows a prior art.

[0020]FIG. 7 shows another prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The embodiments of the printer according to the present inventionwill be explained bellow, with reference to the attached drawings.

[0022]FIGS. 1 and 2 show a side view of a printer in a first embodimentof the present invention. FIG. 1 shows a situation where the printer isinoperative, that is, the maintenance of the print head 12 is beingperformed. FIG. 2 shows the printer in use, that is, a printingoperation is being performed.

[0023] A bottom plate 10 a of the printer body unit 10 is attached tothe bottom plate 31 of the connecting member 30. At the side wall 32 ofthe connecting member 30, a cutter unit 20 is rotatably attached by abolt 34. A platen support member 50 is attached to the cutter unit 20 bya bolt 53. A platen 40 is engaged to an arm 52 of the platen supportmember 50. The connecting member 30, to which the printer body unit 10and the cutter unit 20 are attached, is attached to a roll holding frame1 by a bolt 35.

[0024] Inside of the printer body unit 10, a driving motor 11, a printhead 12 and a paper guide 13 are accommodated. The print head 12 has aprinting surface 12 a and a rear surface 12 b. The printing surface 12 aand the rear surface 12 b are arranged substantially perpendicular tothe bottom plate 10 a of the printer body unit 10.

[0025] In the present embodiment, the cutter unit 20 is a so-calledguillotine cutter wherein a movable blade 22 is moved toward astationary blade 21 by a movable blade driving motor (not shown) to cuta paper P with the edges of the both blades. The roll holding frame 1holds the roll of paper R. A roll cover frame 2 is rotatably attachedaround a shaft 3 of the roll holding frame 1, and the roll cover frame 2can be flipped-up at the time of changing the roll of paper R.

[0026] As is apparent from the comparison of FIG. 1 and FIG. 2, when theprinter is not being used, the cutter unit 20 is rotated at about 90degrees, with respect to when the printer is being used. The movableblade 22 being substantially horizontal when the printer is used becomessubstantially perpendicular when the printer is not being used. When theprinter is not used, the platen 40 attached to the cutter unit 20 islocated on the non-printing surface side of the print head 12 standingsubstantially perpendicular, with respect to the rear surface 12 b ofthe print head. The portion above the print head 12 is wide open,similar to the prior art shown in FIG. 7, and the access to the printhead 12 is easy and maintenance can be easily done. Further, it can bedone by only one motion, while two motions are required in the prior artshown in FIG. 7.

[0027]FIG. 3 shows an enlarged view around the platen 40 when theprinter is being used. An upper plate 51 of a platen mounting member 50is attached to the bottom plate 20 a of the cutter unit 20. Arms 52 aand 52 b, extending downwardly in the drawing from the upper plate 51,support a shaft 41 of the platen 40. The shaft 41 of the platen 40projects in a direction perpendicular to the sheet of the drawing, andthe projected portion is located within a notch 15 which substantiallyhas a U-shape and is formed at the upper part of the side wall 14 of theprinter body unit 10.

[0028] The printer body unit 10 is provided with a platen shaft stopper16 which is generally U-shaped with the left side being open in FIG. 3.The platen shaft stopper 16 is provided so as to be rotatable clockwisearound the pivot Q from the position shown by a solid line and a dottedline in the drawing, and is always forced counterclockwise toward theposition, shown by the solid line and the dotted line, by a spring (notshown).

[0029] Accordingly, when the platen shaft 41 is lowered from abovetoward the notch 15 of the printer body unit 10 so as to be locatedwithin the notch 15, as shown by an alternate long and short dash linein the drawing, the platen shaft 41 pushes the upper arm 16 a of theplaten shaft stopper 16 to rotate the platen shaft stopper 16 clockwise.When the platen shaft 41 passes the upper arm 16 a of the platen shaftstopper 16, the platen shaft stopper 16 returns to the position shown bythe solid line and the dotted line so as to prevent the platen shaft 41from moving upward.

[0030] The platen shaft stopper 16 is provided with a lever (not shown).Upon removing the platen 40 from the printer body unit 10, the lever ismanually operated to rotate the platen shaft stopper 16 clockwise. Then,the platen shaft stopper 16 can be separated from the platen shaft 41.

[0031] Next, the assembly of the printer according to the firstembodiment, as structured and used above, will be explained withreference to an exploded view shown in FIG. 4.

[0032] At first, the platen support member 50 is attached to the cutterunit 20 by the bolt 53. The arm 52 of the platen support member 50,attached to the cutter unit 20, is engaged with the platen 40.

[0033] Then, the bottom plate 10 a of the printer body unit 10 isattached to the bottom plate 31 of the connecting member 30 by the bolt33. Thereafter, the cutter unit 20, having the platen 40 through theplaten support member 50, is rotatably provided on the side wall 32 ofthe connecting member 30. Then, the connecting member 30 having theprinter body unit 10 and the cutter unit 20 is attached to the rollholding frame 1, to complete the assembly.

[0034] Because the present invention according to the first embodimentis assembled as described above, and if, for example, the printer bodyunit 10, the cutter unit 20 and the platen 40 have already been obtainedas discrete components, only the connecting member 30, the platenmounting member 50 for mounting the platen 40 to the cutter unit 20, arenewly required. Thus, less cost is required fro design changes.

[0035] Next, the second embodiment will be explained. FIG. 5 is anexplanatory view of the features of the second embodiment. The secondembodiment is different from the first embodiment in the point that theupper plate 51 of the platen mounting member 50 extends toward the left,in the drawing, and, then, bend downward so as to form a paper guide 53.By doing this, entanglement of the paper P after printing can beprevented at little cost.

[0036] A printer using a roll of paper according to the presentinvention comprises a printer body unit having at least a print headattached thereto and a cutter unit for cutting the paper printed by theprint head, wherein the cutter unit is rotatably attached to the printerbody unit, the cutter unit includes a stationary blade and a movableblade which cooperate, near the print head, to cut the paper, during thecutting operation, the print head is provided with a platen for pressingthe paper against the print head, and the stationary blade, the movableblade and the platen can be displaced from a position above the printhead, by rotating the cutter unit. Accordingly, when the printer is notused, the place above print head is widely open and the maintenance canbe easy.

1. A printer using a roll of paper, comprising a printer body unit having at least a print head attached thereto and a cutter unit for cutting the paper printed by the print head, wherein the cutter unit is rotatably attached to the printer body unit, the cutter unit includes a stationary blade and a movable blade which cooperate, above the print head, to cut the paper during the cutting operation, the print head is provided with a platen for pressing the paper against the print head, and the stationary blade, the movable blade and the platen can be displaced from a position above the print head, by rotating the cutter unit.
 2. A printer using a roll of paper according to claim 1, wherein when the printer is not being used, the cutter unit can be rotated to a position in which the platen is located on the non-printing surface side of the print head, opposite to a printing surface, with respect to an extension line of a rear surface of the print head.
 3. A printer using a roll of paper according to claim 1, wherein a connecting member is attached to the printer body unit and the cutter unit is rotatably attached to the connecting member.
 4. A printer using a roll of paper according to claim 1, wherein the platen is attached to a lower surface of the cutter unit through a platen mounting member.
 5. A printer using a roll of paper according to claim 4, wherein the platen mounting member can also serve as a paper guide for guiding the paper into the cutter unit. 